Time of arrival based correction and verification for uplink channel synchronization

ABSTRACT

A method, apparatus, and a computer-readable storage medium are provided for time of arrival (TOA) based correction for uplink channel synchronization at a user equipment (UE). In an example implementation, the method may include determining a first time of arrival (TOA) index value; receiving, by the user equipment (UE), a first timing advance (TA) correction index value from a network node; and determining, by the user equipment (UE), a first time of arrival (TOA) correction value corresponding to the first timing advance (TA) correction index value. The example implementations may further include determining a first adjusted uplink timing value based at least on the first time of arrival (TOA) correction value and the first timing advance (TA) correction index value; and transmitting, by the user equipment (UE), first uplink data based at least on the first adjusted uplink timing value.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to the application filed under AttorneyDocket No. 0007-292WO1, filed on Sep. 6, 2019, the disclosure of whichis incorporated by reference herein in its entirety.

TECHNICAL FIELD

This description relates to wireless communications, and in particular,to synchronous wireless communications.

BACKGROUND

A communication system may be a facility that enables communicationbetween two or more nodes or devices, such as fixed or mobilecommunication devices. Signals can be carried on wired or wirelesscarriers.

An example of a cellular communication system is an architecture that isbeing standardized by the 3rd Generation Partnership Project (3GPP). Arecent development in this field is often referred to as the long-termevolution (LTE) of the Universal Mobile Telecommunications System (UMTS)radio-access technology. E-UTRA (evolved UMTS Terrestrial Radio Access)is the air interface of 3GPP's Long Term Evolution (LTE) upgrade pathfor mobile networks. In LTE, base stations or access points (APs), whichare referred to as enhanced Node AP or Evolved Node B (eNBs), providewireless access within a coverage area or cell. In LTE, mobile devices,or mobile stations are referred to as user equipments (UE). LTE hasincluded a number of improvements or developments.

5G New Radio (NR) development is part of a continued mobile broadbandevolution process to meet the requirements of 5G, similar to earlierevolution of 3G & 4G wireless networks. In addition, 5G is also targetedat the new emerging use cases in addition to mobile broadband. A goal of5G is to provide significant improvement in wireless performance, whichmay include new levels of data rate, latency, reliability, and security.5G NR may also scale to efficiently connect the massive Internet ofThings (IoT), and may offer new types of mission-critical services.Ultra-reliable and low-latency communications (URLLC) devices mayrequire high reliability and very low latency.

SUMMARY

A method, apparatus, and a computer-readable storage medium are providedfor time of arrival (TOA) based uplink channel synchronization.

In an implementation, an example method may comprise determining, by auser equipment (UE), a first time of arrival (TOA) index value;receiving, by the user equipment (UE), a first timing advance (TA)correction index value from a network node; determining, by the userequipment (UE), a first time of arrival (TOA) correction valuecorresponding to the first timing advance (TA) correction index value;determining, by the user equipment (UE), a first adjusted uplink timingvalue based at least on the first time of arrival (TOA) correction valueand the first timing advance (TA) correction index value; andtransmitting, by the user equipment (UE), first uplink data based atleast on the first adjusted uplink timing value.

In another implementation, an example method may comprise determining,by a user equipment (UE), a first time of arrival (TOA) based timingadvance index value; receiving, by the user equipment (UE), a firsttiming advance (TA) correction index value from a network node;validating, by the user equipment (UE), the first timing advance (TA)correction index value received from the network node, the validatingbased at least on the first time of arrival (TOA) based timing advanceindex value; and transmitting, by the user equipment (UE), a firstuplink data based at least on the first timing index (TA) value that hasbeen successfully validated.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a wireless network according to an exampleimplementation.

FIG. 2A illustrates signal propagation delay characteristics for ahigh-speed example scenario, according to an example implementation.

FIG. 2B illustrates signal propagation delay characteristics as afunction of time, according to an additional example implementation.

FIG. 2C illustrates signal propagation delay characteristics, accordingto another additional example implementation.

FIG. 3 illustrates an activity diagram for determining time of arrival(TOA) based timing advance (TA) correction values, according to anexample implementation.

FIGS. 4A-4H illustrate sT_(X)(X) function in various scenarios,according to some example implementations.

FIG. 5 is a flow diagram illustrating time of arrival based uplinkchannel synchronization, according to an example implementation.

FIG. 6 is a flow diagram illustrating time of arrival (TOA) based uplinkchannel synchronization for transmission of data from a UE, according toan example implementation.

FIG. 7 is a block diagram of a node or wireless station (e.g., basestation/access point or mobile station/user device/UE), according to anexample implementation.

DETAILED DESCRIPTION

FIG. 1 is a block diagram of a wireless network 130 according to anexample implementation. In the wireless network 130 of FIG. 1, userdevices (UDs) 131, 132, 133 and 135, which may also be referred to asmobile stations (MSs) or user equipment (UEs), may be connected (and incommunication) with a base station (BS) 134, which may also be referredto as an access point (AP), an enhanced Node B (eNB) or a network node.At least part of the functionalities of an access point (AP), basestation (BS) or (e)Node B (eNB) may also be carried out by any node,server or host which may be operably coupled to a transceiver, such as aremote radio head. BS (or AP) 134 provides wireless coverage within acell 136, including to user devices 131, 132, 133 and 135. Although onlyfour user devices are shown as being connected or attached to BS 134,any number of user devices may be provided. BS 134 is also connected toa core network 150 via a S1 interface 151. This is merely one simpleexample of a wireless network, and others may be used.

A user device (user terminal, user equipment (UE)) may refer to aportable computing device that includes wireless mobile communicationdevices operating with or without a subscriber identification module(SIM), including, but not limited to, the following types of devices: amobile station (MS), a mobile phone, a cell phone, a smartphone, apersonal digital assistant (PDA), a handset, a device using a wirelessmodem (alarm or measurement device, etc.), a laptop and/or touch screencomputer, a tablet, a phablet, a game console, a notebook, and amultimedia device, as examples, or any other wireless device. It shouldbe appreciated that a user device may also be a nearly exclusive uplinkonly device, of which an example is a camera or video camera loadingimages or video clips to a network.

In LTE (as an example), core network 150 may be referred to as EvolvedPacket Core (EPC), which may include a mobility management entity (MME)which may handle or assist with mobility/handover of user devicesbetween BSs, one or more gateways that may forward data and controlsignals between the BSs and packet data networks or the Internet, andother control functions or blocks.

In addition, by way of illustrative example, the various exampleimplementations or techniques described herein may be applied to varioustypes of user devices or data service types, or may apply to userdevices that may have multiple applications running thereon that may beof different data service types. New Radio (5G) development may supporta number of different applications or a number of different data servicetypes, such as for example: machine type communications (MTC), enhancedmachine type communication (eMTC), Internet of Things (IoT), and/ornarrowband IoT user devices, enhanced mobile broadband (eMBB), andultra-reliable and low-latency communications (URLLC).

IoT may refer to an ever-growing group of objects that may have Internetor network connectivity, so that these objects may send information toand receive information from other network devices. For example, manysensor type applications or devices may monitor a physical condition ora status, and may send a report to a server or other network device,e.g., when an event occurs. Machine Type Communications (MTC or machineto machine communications) may, for example, be characterized by fullyautomatic data generation, exchange, processing and actuation amongintelligent machines, with or without intervention of humans. Enhancedmobile broadband (eMBB) may support much higher data rates thancurrently available in LTE.

Ultra-reliable and low-latency communications (URLLC) is a new dataservice type, or new usage scenario, which may be supported for NewRadio (5G) systems. This enables emerging new applications and services,such as industrial automations, autonomous driving, vehicular safety,e-health services, and so on. 3GPP targets in providing up to e.g., 1 msU-Plane (user/data plane) latency connectivity with 1-1e-5 reliability,by way of an illustrative example. Thus, for example, URLLC userdevices/UEs may require a significantly lower block error rate thanother types of user devices/UEs as well as low latency. Thus, forexample, a URLLC UE (or URLLC application on a UE) may require muchshorter latency, as compared to a eMBB UE (or an eMBB applicationrunning on a UE).

The various example implementations may be applied to a wide variety ofwireless technologies or wireless networks, such as LTE, LTE-A, 5G, IoT,MTC, eMTC, eMBB, URLLC, etc., or any other wireless network or wirelesstechnology. These example networks, technologies or data service typesare provided only as illustrative examples.

Multiple Input, Multiple Output (MIMO) may refer to a technique forincreasing the capacity of a radio link using multiple transmit andreceive antennas to exploit multipath propagation. MIMO may include theuse of multiple antennas at the transmitter and/or the receiver. MIMOmay include a multi-dimensional approach that transmits and receives twoor more unique data streams through one radio channel. For example, MIMOmay refer to a technique for sending and receiving more than one datasignal simultaneously over the same radio channel by exploitingmultipath propagation. According to an illustrative example, multi-usermultiple input, multiple output (multi-user MIMIO, or MU-MIMO) enhancesMIMO technology by allowing a base station (BS) or other wireless nodeto simultaneously transmit or receive multiple streams to different userdevices or UEs, which may include simultaneously transmitting a firststream to a first UE, and a second stream to a second UE, via a same (orcommon or shared) set of physical resource blocks (PRBs) (e.g., whereeach PRB may include a set of time-frequency resources).

Also, a BS may use precoding to transmit data to a UE (based on aprecoder matrix or precoder vector for the UE). For example, a UE mayreceive reference signals or pilot signals, and may determine aquantized version of a DL channel estimate, and then provide the BS withan indication of the quantized DL channel estimate. The BS may determinea precoder matrix based on the quantized channel estimate, where theprecoder matrix may be used to focus or direct transmitted signal energyin the best channel direction for the UE. Also, each UE may use adecoder matrix may be determined, e.g., where the UE may receivereference signals from the BS, determine a channel estimate of the DLchannel, and then determine a decoder matrix for the DL channel based onthe DL channel estimate. For example, a precoder matrix may indicateantenna weights (e.g., an amplitude/gain and phase for each weight) tobe applied to an antenna array of a transmitting wireless device.Likewise, a decoder matrix may indicate antenna weights (e.g., anamplitude/gain and phase for each weight) to be applied to an antennaarray of a receiving wireless device. This applies to UL as well when aUE is transmitting data to a BS.

For example, according to an example aspect, a receiving wireless userdevice may determine a precoder matrix using Interference RejectionCombining (IRC) in which the user device may receive reference signals(or other signals) from a number of BSs (e.g., and may measure a signalstrength, signal power, or other signal parameter for a signal receivedfrom each BS), and may generate a decoder matrix that may suppress orreduce signals from one or more interferers (or interfering cells orBSs), e.g., by providing a null (or very low antenna gain) in thedirection of the interfering signal, in order to increase a signal-tointerference plus noise ratio (SINR) of a desired signal. In order toreduce the overall interference from a number of different interferers,a receiver may use, for example, a Linear Minimum Mean Square ErrorInterference Rejection Combining (LMMSE-IRC) receiver to determine adecoding matrix. The IRC receiver and LMMSE-IRC receiver are merelyexamples, and other types of receivers or techniques may be used todetermine a decoder matrix. After the decoder matrix has beendetermined, the receiving UE/user device may apply antenna weights(e.g., each antenna weight including amplitude and phase) to a pluralityof antennas at the receiving UE or device based on the decoder matrix.Similarly, a precoder matrix may include antenna weights that may beapplied to antennas of a transmitting wireless device or node. Thisapplies to a receiving BS as well.

In synchronous wireless communications, for example, LTE, 5G/NR, etc., atiming advance (TA) correction index value and/or update(s) provided bya network node (e.g., a base station) are essential for synchronizinguplink transmissions as downlink transmissions are used by a userequipment (UE) as a reference for the uplink transmissions. Without sucha synchronization mechanism, the UE may not be able to access networkresources to transmit data using uplink channel(s).

A base station (e.g., eNB, gNB, etc.) may calculate a TA correctionindex value (e.g., an initial TA correction index value) and share theTA correction index value with a UE via a TA command during a randomaccess (RA) procedure initiated by the UE. For example, the TA commandmay be a part of a RACH response (e.g., Msg2 of a four-step randomprocedure or MsgB of a two-step random access procedure). In addition,the base station may update the TA correction value (or update theinitial TA correction value) via a medium access control (MAC) controlelement (CE) update procedure, as defined in 3GPP Specifications (e.g.,3GPP 36.214).

In terrestrial wireless communication systems (e.g., ground basedwireless communication networks), lower UE speeds may allow for properapplication of TA correction index value and/or MAC CE updates withoutsignificant signaling overhead. For example, in LTE, 1 TA isapproximately 78 meters and the UE needs to be at/below a speed of 280.8kms/hr in or against the direction of a base station antenna system toreceive one MAC CE TA update in 1 second. For example, for a LTE signalframe size of 10 ms, a MAC CE TA update is applied in 1 out of 100frames and other 99 frames may be used for other signaling or datatransmissions.

However, in high-speed/very high-speed scenarios, the UE or base station(or both of them) may be in motion. In such scenarios, additional TAcorrection values may be needed. But, the additional TA correctionvalues may require more downlink radio resources for maintainingsynchronization at the UE. In some more such scenarios, for example, innon-terrestrial network (NTN) applications, a satellite with a basestation (e.g., a satellite cell) may be moving at a speed of 7.5 kms/s(e.g., 27,000 kms/hr) and for a UE with a speed of 0 km/s (e.g., astationary UE), approximately 96 MAC CE TA updates per second may beneeded to maintain the required synchronization, for example,synchronization based on 3GPP LTE standards as described above.

Therefore, there is desire/need to efficiently apply TA correctionvalues if motion patterns of high-speed base station and/or UE are notknown, the relative speeds of base station and/or UE are rapidlychanging, and/or when the position of base station and/or UE are notknown.

The present disclosure describes a time of arrival (TOA) based uplinkchannel synchronization mechanism at a user equipment (UE). In anexample implementation, the method may include determining a first timeof arrival (TOA) index value; receiving, by the user equipment (UE), afirst timing advance (TA) correction index value from a network node;and determining, by the user equipment (UE), a first time of arrival(TOA) correction value corresponding to the first timing advance (TA)correction index value. The example implementations may further includedetermining a first adjusted uplink timing value based at least on thefirst time of arrival (TOA) correction value and the first timingadvance (TA) correction index value; and transmitting, by the userequipment (UE), first uplink data based at least on the first adjusteduplink timing value.

FIG. 2A illustrates signal propagation delay characteristics 200 for ahigh-speed example scenario, according to an example implementation. Inan example implementation, for example, two high-speed nodes, e.g., eNB202 and UE 204, may establish a wireless connection, eNB 202 being aserving cell of UE 204.

In some implementations, for example, eNB 202 may be moving much fasterthan UE 202. For example, the eNB may be moving at 4× the speed of theUE (e.g., V_(eNB)=4 V_(UE)). This is an example implementation and not alimitation as the eNB and/or UE may move with different speeds in otherexample implementations. The speeds at which the nodes are moving and/orthe pattern motions have illustrative character.

As illustrated in FIG. 2A, eNB 202 may broadcast information (e.g.,continuously) containing the time a signal is physically transmitted, T₀(e.g., time of physical transmission of the signal or signal physicaltransmission time) from eNB 202. The signal transmitted from the eNB maybe a signal frame, sub-frame, symbol, etc., and may be used by the UE asa reference signal for measurement of signal propagation delay. In someimplementations, for example, the selection of the signal granularity(e.g., frame or sub-frame or symbol) by the UE may be based on maximumrange and/or required update rate for time of arrival (TOA) basedmeasurements.

For instance, in 1 millisecond a distance of 300 km is travelled bylight or any other microwave signal. If reference signal is sent every 1millisecond, in a cell with range of 300 kms, this reference signal maybe the only reference signal. This may ensure unambiguity as only thisone value may be present in the cell for the entire range. If wedecrease this period, e.g., to 0.5 millisecond (˜distance 150 kms) theremay be 2 such signals within the cell range (300 kms). It may result inambiguity. This issue is important when we consider how T₀ value shouldbe reported, e.g., the format: HH:MM:SS:MS:US:NS. This may be shortenedto US:NS if reference signal is sent unambiguously (e.g., 1 millisecondin 300 kms cell range) or MS:US:NS if more frequent updates arerequired.

In addition, this may be related to relative motion patterns, asillustrated for example, in FIGS. 4A-H. For example, if the relativedistance between UE and eNB has linear representation (e.g., FIG. 4F),the update rate may be lower as UE may still predict/calculate necessarycorrections. However, if the motion pattern has non-linear (e.g., FIG.4D) or unpredictable characteristics (e.g., FIG. 4B), more frequentupdates may be needed, as calculations or predictions may not be validor correct for longer periods.

Moreover, a UE may also use as reference other signals than thosecontaining T₀. This may be possible as LTE/5G frame structure issynchronous. For example. LTE frame (10 milliseconds) is exactly 307200T_(s) and UE may just add 307200 T_(s) to the last received frame withT₀ to have most current value. Any difference in propagation delay maybe also detected with such assumption. Thus, UE may change measurementgranularity without the need for higher T₀ update rate (t_(P)) assumingthat transmission is a synchronous transmission.

In some implementations, eNB 202 may broadcast a signal at pre-definedtime periods T₀₀, T₀₁, T₀₂, etc., with an update time period of t_(P).The broadcasted signal may be received, at UE 204, at time periods T₁₀,T₁₁, T₁₂, etc. In an example implementation, update time period t_(P)may be the same between the broadcasted signals. In another exampleimplementation, update time period t_(P) may vary between thebroadcasted signals (may be referred to as t_(P) pattern). For example,the update time period t_(P), for example, between T₀₀ and T₀₁ and T₀₁and T₀₂ may be equal (e.g., 5 ms) or it may vary (e.g., 5 ms and 10 ms)and/or eNB 202 may inform UE 204 about the t_(P) patterns. Moreover, insome implementations, for example, the broadcasting of the signal and/ort_(P) patterns may be associated with system information block (SIB)transmissions, for example, system information block 16 (SIB16) which isalso used for Global Positioning System (GPS) related information (orsatellite-related positioning information).

In an example implementation, the signal emitted (e.g., transmitted) byeNB 202 at time T₀₀ 220 may be received by UE 204 at time T₁₀ 222 andthe data (e.g., T₀₀ and T₁₀) may be latched (e.g., saved, stored, etc.)at UE 204, for example, in an associated UE register. The differencebetween T₁₀ and T₀₀ (e.g., T₁₀-T₀₀) may correspond to (or considered as)signal propagation delay, T_(X) (e.g., microwave signal propagationdelay) as shown by, for example, [Eq. 1] below, assuming that theprocessing times at eNB 202 and/or UE 204 are stable and/or may becompensated. For example, in [Eq. 1], T_(X) represents propagation delaytime for sample X, T_(0X) represents transmission time of sample X ateNB 202 and T_(1X) represents reception time of sample X at UE 204.

T _(X) =T _(1X) −T _(0X)   [Eq. 1]

FIG. 2B illustrates signal propagation delay characteristics 240 as afunction of time, according to an additional example implementation.

In some implementations, propagation delays (or propagation delay times)may change as a function of time and/or may depend on relative motionpatterns of the nodes (e.g., speed/heading of eNB/UE) when the nodes(e.g., eNB 202/UE 204) are in motion. FIG. 2B illustrates howpropagation delay T_(X) changes in time domain in an exampleimplementation. For example, T_(X) may be expressed in terms oftransmission time interval (TTI) scale for providing information aboutrelative distance between the nodes (eNB/UE) with respect to radioresource control (RRC) signaling. In FIG. 2B, a TTI of 1 ms is used forillustration/explanation purposes (and not as a limitation).

In an example implementation, the changes in propagation delay may beexpressed as a function of time, for example, as shown in [Eq. 2] below,where St_(X)(X) 250 represents speed of distance change for sample X,T_(X)(X) represents propagation delay time for sample X at t_(P), andT_(X−1)(X−1) represents propagation delay for sample X−1, where timeX=(X−1)+t_(P).

sT _(X)(X)=T _(X)(X)−T _(X−1)(X−1)   [Eq. 2]

In other words, 240 of FIG. 2B represents function sT_(X)(X) which mayillustrate how signal propagation delay varies with respect to updatetime period t_(P) and/or characteristics of the relative movements ofthe nodes.

FIG. 2C illustrates signal propagation delay characteristics 280,according to an additional example implementation. A more detailed viewfor sT_(X)(X) characteristics is illustrated in FIG. 2C.

For example, in FIG. 2C, the axis related to propagation delays may bescaled and expressed as t_(Pd)X values. In some implementations, forexample, t_(Pd)X values may correspond to TA unit values for a givenstandard as specified by, for example, [Eq. 3] below.

1 t _(Pd) X=1/2 TA   [Eq. 3]

In some implementations, for example, using data from FIG. 2B, a speedof distance change between eNB 202 and UE 204 may be calculated as shownbelow in [Eq. 4].

t ₁(1)=T ₁(1)−T ₀(0)=T ₁(5 ms)−T ₀(0 ms)=6 t _(Pd)−10 t_(Pd)=−4 t _(Pd)  [Eq. 4]

That is, as shown in FIG. 2C, within one t_(P) period, which may be 5ms, relative distance between eNB 202 and UE 204 decreased by 4 t_(Pd),which for this example implementation may mean approximately 156 m(e.g., equivalent to 2 TAs for LTE). Considering that during 5 ms, adistance of approximately 1500 kms may be travelled by a microwavesignal, unambiguity may be achieved within such range. In someimplementations, other means of coding (e.g., mode interlace pattern,different coding, different carrier frequency, etc.) may be consideredto extend this period and/or keep unambiguity continuous.

Further, as illustrated in FIG. 2C, a UE provided with TOA data (e.g.,signal physical transmission (T₀) time and TOA reference data updaterate (e.g., t_(P))) may be able to measure signal propagation delayswhich in turn may be used for relative distance assessments. Assumingthat microwave speed is constant for microwave signals, such distancemay be used to calculate TA correction values (or TA drift corrections).In an example implementation, a pattern sT_(X)(X) may be determined,especially for frequent t_(P) updates, which may enable prediction forobjects (eNBs/UEs) moving at high-speed/very high-speed. For example, ina fast-moving scenario, eNB TA-based synchronization mechanism may failas provided TA values may be not up to date at the time ofapplicability, as distance may change more than that estimated by eNBdue to processing and transmission delays. Frequent t_(P) updates alsomeans better accuracy if motion pattern is non-linear or irregular, asrelative distance may be more accurately measured, and then providedcorrections may be more accurate.

FIG. 3 illustrates an activity diagram 300 for determining TOA based TAcorrection values, according to an example implementation. In someimplementations, for example, the determined TA correction values may beapplied (e.g., added, subtracted, etc.) to the corresponding TAcorrection values received from an eNB to compensate for rapid changesin distance between eNB and UE.

In some implementations, for example, at 310, eNB 202 may be in motionand may be configured to transmit (e.g., broadcast) TOA related data,also referred to as TOA data set, to UE 204 (UE 202 may be in motion aswell in some implementations).

At 320, UE 204 may receive a first TOA data set, tp1, sent at time Tofrom the eNB. In an example implementation, the first TOA data set tp1may include transmission time T₀ and/or update time period t_(P). UE 204may receive the first TOA data set tp1 at time T₁. Upon receiving thefirst TOA data set tp1, UE 204 may determine the propagation delay,e.g., a first propagation delay, T_(TOA)(tp1=0), and T_(TOA1) may beused to describe first TOA distance measurement. In an exampleimplementation, the propagation delay for T_(TOA) (tp1=0) may bedetermined based on [Eq. 1], for example, (T₁−T₀), and stored at the UE.

After a time period t_(P), at 330, UE 204 may receive a second TOA dataset, tp2. Upon receiving the second TOA data set tp2, UE 204 maydetermine the propagation delay, e.g., a second propagation delay,T_(TOA) (tp2=0+tp1) based on [Eq. 1]. It should be noted that the thatthe next measurement is performed after agreed update period, e.g., tp.In some implementations, for example, UE 204 may also determine speed ofrelative distance change, sT_(X)(X)), T_(TOA) (X=2), based on forexample, [Eq. 2], and stored at the UE. It should be noted that at leasttwo independent measurements are necessary to estimate the speed ofpropagation delay change.

After an additional time period t_(P), at 340, UE 204 may receive athird TOA data set, tp3. Upon receiving the third TOA data set tp3, UE204 may determine the acceleration of relative distance change,aT_(X)(X), based on, for example, [Eq. 5]. In some implementations, forexample, TOA based TA drift prediction and compensation may be possible,as aT_(X)(X) vector (e.g., value/direction) may be determined.

aT _(TOA)(X)=(sT _(X)(X)−sT _(X−1)(X−1))/t _(P(X−(X−1)))   [Eq. 5]

That is, once acceleration/deceleration rate of relative distance changeis determined, it may be possible to predict and/or compensate the valueat the time of its applicability. For example, when such uplinktransmission reaches eNB, it may be fully synchronized, even if thedistance change is changing frequently. The compensation mechanism mayuse the UE's last position (e.g., last distance measurement) and addnecessary correction based on motion pattern.

In some implementations, for example, UE 204 may use aT_(X)(X)characteristics to determine TOA based T_(TOA) correction values to TAbudget as UE may be provided with relative distance change patterns. Inaddition, the UE may apply proper uplink correction values to compensatefor eNB motion so that UE uplink transmission (for example, transmittedfrom UE 204 to eNB 202 at 350) may reach the eNB at new location withfull synchronization, for example, at 360. Such TA drift prediction maybe necessary for the next uplink transmission and not as it is currentlyused for TA where changes are applied from 6^(th) TTI. In other words,UE may receive TA correction from eNB for uplink channelsynchronization. Using TOA method, UE may calculate TOA-based distanceto eNB, which may be then converted to TA index value form. Due tobetter accuracy (Ts), this method may be more accurate. If comparison ofTA (eNB) and TOA TA shows difference (e.g., due to motion), a TOAcorrection to TA overall budget may be added. Timing Advance (TA)TOA-based correction to TA budget may include processing (e.g.,constant) and transmission (e.g., depends on a distance) delays toensure that such uplink transmission will reach the receiver (e.g., eNBat proper time, e.g., fully synchronized, even in motion).

In some implementations, for example, an eNB that may be receiving TOAbased T_(TOA) corrected uplink transmissions may be unaware that suchcorrections have been applied by the UE as no additional signaling tothe eNB may be needed. The UE uplink transmissions received at the eNBmay be then correctly decoded as no TA drift will be present (or withintolerance limits). As illustrated, high or very-high speed of UE, eNB orboth may be successfully compensated for RRC connection establishmentand/or maintenance of the connection.

In some implementations, for example, the above describedmechanism/procedure may require at least 3 TOA data sets to beconsidered during relatively short update time period t_(P). Inaddition, as the UE may receive eNB broadcasts before an RRC connectionis requested (e.g., terrestrial wireless networks), the proposedmechanism/procedure may not delay connection establishment. In otherwords, three TOA data sets may be required if relative distance changepattern is irregular. However, the UE may receive necessary TOA datasets before the RRC connection is requested so that there may be nodelay (e.g., additional delay) in establishing the connection. It shouldbe noted that the delay may last up to 3 tp if exact value is needed (or3 measurements—2 tp, counting time between 3 independent measurements).

Moreover, the proposed mechanism/procedure does not require positioningreports and is based on signal propagation delays (or signal propagationdelay measurements). An advantage of this approach is that any changesin the propagation medium (e.g., vacuum, air) in signal propagationdelays are naturally compensated. In addition, the position of the UEsis not revealed (e.g., UE's position not reported to the eNB in order toestablish the connection).

In some implementations, for example, when position-based mechanism foruplink channel synchronization is considered: a relative distancebetween eNB and UE (when both in motion) may be determined if both eNB(X, Y, Z) and UE (X, Y, Z) coordinates are known. In such a scenario,for example, a distance may be calculated based on [Eq. 6], and it maybe described as position-based TA correction.

$\begin{matrix}{{D_{{UE}{eNB}}\left( {X,Y,Z} \right)} = \sqrt{\left( {X_{eNB} - X_{UE}} \right)^{2} + \left( {Y_{eNB} - Y_{UE}} \right)^{2} + \left( {Z_{eNB} - Z_{UE}} \right)^{2}}} & \left\lbrack {{Eq}.6} \right\rbrack\end{matrix}$

In some implementations, the position-based mechanism described abovemay be used for verification and antenna gain optimization.

In some implementations, for example, the TOA based uplink channelsynchronization may be used for: a) TOA based TA correction T_(TOA) tocompensate high drift of TA value due to high speed scenario and b) TOAbased TA T_(TOA) correction and T_(TOAVAL) value for verificationpurpose.

Therefore, as described above, the TOA based procedure described abovemay be used for provision of T_(TOA) correction values which may beadded to the overall budget of TA value to cover potentially rapidlychanges of relative distance between UE and serving eNB which otherwisemay require significant number of MAC CE TA updates.

FIGS. 4A-4H illustrate sT_(X)(X) function in various scenarios,according to some example implementations. In an example implementation,the prediction of TOA based correction values or TOA based values may bedetermined as specified in aT_(X)(X) where information about changes ofthe speed in a given time may indicate an acceleration of such change.It should be noted that the mechanisms/procedures described in thisdisclosure may also be used to compensate predicted TA drift in uplinktransmission based on change history and function. As illustrated inFIGS. 4A-4H, the mechanisms/procedures described in the presentdisclosure may be applied for various other scenarios as well,including, for example, ground based mobile network applications (e.g.,terrestrial network applications) and non-terrestrial networkapplications (e.g., FIG. 2A).

In some implementations, for example, FIGS. 4A and 4B illustratesT_(X)(X) (410, 420) for maneuvering (e.g., motion pattern may changerapidly) and accelerating objects, according to some exampleimplementations.

In some implementations, for example, FIGS. 4C and 4D illustratesT_(X)(X) (430 and 440) for eNB/UE with constant speeds but differentheading or eNB with constant speed and a static UE, according to someexample implementations.

In some implementations, for example, FIGS. 4E and 4F illustratesT_(X)(X) (450 and 460) for static eNB and moving UE (reference to aterrestrial wireless network), according to some exampleimplementations.

In some implementations, for example, FIGS. 4G and 4H illustratesT_(X)(X) (470 and 480) for two moving objects with no differences inrelative speed and distance.

FIG. 5 is a flow diagram 500 illustrating time of arrival based uplinkchannel synchronization, according to an example implementation.

At 502, UE 204 may be in a radio resource control (RRC)_IDLE state.

At 504, UE 204 may receive master information block (MIB) and/or systeminformation blocks (SIBs may include SIB1, SIB2, SIB3, . . . , andSIB16) from eNB 202. eNB 202, in an example implementation, maybroadcast the MIB on a physical broadcast channel (PBCH) and the SIBs ona physical downlink shared channel (PDSCH), via RRC messages.

In some implementations, for example, a SIB (for example, SIB16) mayinclude TOA data set(s). A TOA data set may include signal physicaltransmission times (e.g., T₀) and/or an update time period t_(P), asdescribed above in reference to FIG. 3.

At 506, UE 204 may determine, for example, one or more of Tx, sT_(X)(X),aT_(X)(X), T_(TOA), T_(TOAVAL), etc. (as described in reference to FIGS.2A-2C (above) and FIGS. 4A-4H and 6 (below)) based on TOA data set(e.g., first, second, third data sets as described above in reference toFIG. 3) and/or other information (e.g., signal physical reception time,etc.) available at the UE.

At 508, UE 204 may initiate a random access (RA) procedure, for example,to transition the UE from RRC_IDLE state to RRC_CONNECTED state (or anyother state that is not an RRC_IDLE state). In some implementations, forexample, the UE may initiate RA procedure in response to data beingavailable for transmission from the UE (or due to any other trigger asdefined in 3GPP Specifications). The RA procedure may be used by the UEto synchronize with the network (e.g., cells). In some implementations,the RA procedure may be a four-step RA procedure or a two-step RAprocedure depending on configuration.

In an example implementation, the four-step RA procedure may includeMessages 1, 2, 3, and/or 4 (also referred to as Msg1, Msg2, Msg3, andMsg4) exchanged between UE 204 and eNB 202 as following: a) Msg1-UE 204selects one of the available preambles and sends it to the eNB, forexample, using a random access radio network temporary identity(RA-RNTI) as an identifier; b) Msg2—eNB 202 sends random access response(RAR) to the UE on a downlink shared channel (DL-SCH) addressed to theRA-RNTI calculated from the timeslot in which the preamble was sent. Insome implementations, the Msg2 may include the following information:temporary cell-RNTI (C-RNTI)—eNB gives another identity to UE which iscalled temporary C-RNTI (cell radio network temporary identity) forfurther communication; Timing Advance Value: eNB informs the UE tochange its timing so the UE can compensate for the delay caused due tothe distance between the UE and eNB; and Uplink Grant Resource: eNB willassign initial resource to the UE so that the UE can use UL-SCH (uplinkshared channel); c) Msg3—Using UL-SCH, the UE may send RRC connectionrequest message to the eNB. The UE may be identified by temporary C-RNTI(assigned previously by the eNB). In some implementations, Msg3 mayinclude the following—UE identity (TMSI or Random Value)—the TMSI may beused if the UE has previously connected to the same network. With theTMSI value, the UE may be identified in the core network; random valueis used if the UE is connecting for the very first time to network. Therandom value or the TMSI may be needed as the temporary-CRNTI may havebeen assigned to more than one UEs previously, due to multiple requestscoming at same time; and connection establishment cause: this shows thereason why the UE needs to connect to network; d) Msg4—eNB responds withcontention resolution message to the UE whose message was successfullyreceived in Step 3. This message is addressed towards the TMSI value orrandom number (from previous steps) but may include the new C-RNTI whichmay be used for the further communication.

In another example implementation, the two-step RA procedure may includetwo messages, Messages A and B (referred to as MsgA and MsgBrespectively). In some implementations, in the two-step RACH procedure,MsgA may include Msg. 1 (preamble signal) and Msg3 (data signal) of thefour-step RACH procedure and MsgB may include Msg2 (random accessresponse) and Msg4 (contention resolution) of the four-step RAprocedure.

At 509, UE 204 may determine, for example, one or more of Tx, sT_(X)(X),aTX(X), T_(TOA), T_(TOAVAL), etc. (as described in reference to FIGS.2A-2C (above) and FIGS. 4A-4H and 6 (below)), similar to 506 above, butbased on a most up to date TOA data set (e.g., a second data set asdescribed above in reference to FIG. 3) and/or other information (e.g.,signal physical reception time, etc.) available at the UE. It should benoted that 509 is shown in FIG. 5 to indicate that the most up to dateTOA measurements are used for RRC. This (three independent measurementsfor calculating values) is not intended as a limitation. In fact, it maybe considered as a continuous process and the most up to date values maybe used, if needed for RRC. In the case of RA, one TOA data set may besufficient to initiate RACH procedure. However, in a high speedscenario, UE needs to know the pattern of relative distance change.Then, the UE may compare values received from eNB TA correction anddecide whether TA compensation is needed due to TA drift. By having 3TOA data sets, the UE may predict and compensate TA (and finally uplinkchannel timing adjustment) more accurately.

At 510, UE 204 may send Msg1 of the four-step RA procedure to eNB 202.As described above, Msg1 of the RA procedure includes a RA preamble.

Optionally, in some implementations, for example, UE 204 may includeT_(TOA) or T_(TOAVAL) values in Msg1. In some implementations, eNB 202may use the TOA based correction values received from the UE foradjusting the TA correction index values for the following uplinktransmissions. For example, in an implementation, the UE may validatethe timing advance (TA) correction values received from the networknode, the validation being performed based at least on the time ofarrival (TOA) values.

At 512, UE 204 may receive Msg2 of the four-step RA procedure from eNB202. As described above, Msg2 of the RA procedure includes RA response.In some implementations, for example, the RAR/Msg2 may include a TAcommand which may contain a TA correction value.

At 514, UE 204 may apply TOA correction values to the TA correctionindex value received from eNB 202 as shown below in [Eq. 7] and [Eq. 8].In an example implementation, the T_(TOA) correction values may bedetermined based on the following:

ΔT _(toa) =T _(A) −T _(toa)   [Eq. 7]

ΔT _(toa) =T _(A) −T _(toaval)   [Eq. 8]

It should be added that TOA based TA correction may also have indexvalue representation, similar to TA. The change may be integer value anddefined by TA minimal step (1 TA=78 m in this case).

At 516, UE 204 may send Msg3 to UE 202. As described above, Msg3 of theRA procedure may be a RRC connection request.

At 518, UE 204 may receive Msg4 from eNB 202. As described above, Msg 4of the RA procedure includes RRC connection set up message.

At 520, UE 204 sends RRC setup complete message to eNB 202 uponsuccessful reception of Msg4 (and or any related configuration based onMsg4).

At 522, upon reception of the Msg4 from eNB 202, UE 204 transitions toRRC_CONNECTED state.

At 524, in some implementations, for example, UE 204 may be in motion.

At 525, UE 204 may determine, for example, one or more of Tx, sT_(X)(X),aTX(X), T_(TOA), T_(TOAVAL), etc. (as described in reference to FIGS.2A-2C (above) and FIGS. 4A-4H and 6 (below)), similar to 506/509 above,but based on a newer (most up to date) TOA data set as described abovein reference to FIG. 3 and/or other information (e.g., signal physicalreception time, etc.) available at the UE. This indicates that TOA basedcorrection process is a continuous process, the corrections may bedifferent, and the changes may be applied more frequently but directly,without additional signaling as in case of MAC CE TA Update.

At 526, UE 204 may transmit uplink data to eNB 202. In someimplementations, for example, UE 204 may transmit uplink data based onthe adjusted uplink timing value which may be based on the following:

N _(TOA)1=(T _(A) +ΔT _(toa))*16*T _(s)[s]  [Eq. 9]

At 528, UE 204 may receive media access control (MAC) control element(CE) TA updates from eNB 202. The MAC CE TA updates are required at theUE for continuous synchronization of the uplink. In an exampleimplementation, the MAC CE TA updates are sent to the UE when the UE isin RRC_CONNECTED state.

At 530, UE 204 may apply TOA correction values to the MAC CE updatevalues received from eNB 202 based on the following:

N _(TA,new) =N _(TA,old)+(T _(A) +ΔT _(toa)−31)*16   [Eq. 10]

In some implementations, for example, continuous uplink channelsynchronization may also be provided by [Eq. 9] as TOA based correctionvalue added to uplink channel timing adjustment budget may have similarmeaning as MAC CE TA update. eNB may measure quality of UE uplinkchannel synchronization and may trigger MAC CE TA update ifsynchronization needs to be maintained. As synchronization may becontinuously achieved by TOA based correction, MAC CE TA update may notbe triggered or may be triggered less frequent.

It should be noted that TOA-based correction may be added in variousways. In one example implementation, as specified in [Eq. 10], where TOAcorrection may be added to TA value provided in MAC CE TA Update, whichis reflected in the equation. Thus, especially for high speed scenarioor high dynamics of relative distance change, a TOA based additionalcompensation may improve uplink channel timing adjustment and may beapplied together with MAC CE TA update. In another exampleimplementation, TOA based correction may be based on [Eq. 9] whichcorresponds to initial uplink channel timing adjustment and may be usedbased on TA provided in the TA Command. TOA based correction added tothis timing adjustment budget ensures that uplink channel iscontinuously maintained, as any changes related to UE mobility may becompensated by this correction. Thus, an eNB which analyzes quality ofuplink channel synchronization may not trigger MAC CE TA update, asthere may be no need for such connection, even if UE is in motion. MACCE TA update may, however, be triggered by a related timer, but UEmobility may not trigger it. In such a case, reduction in the number ofMAC CE TA updates may be achieved. That is, an example implementationbased on [Eq. 9], MAC CE TA updates may be less frequent.

In an example implementation, the application of TOA correction valuesto the MAC CE update values may determine the adjusted uplink timingvalue.

At 532, UE 204 may transmit uplink data to eNB 202. In someimplementations, for example, UE 204 may transmit uplink data based onthe adjusted uplink timing value determined at 530.

Therefore, as described above, TOA based adjusted uplink channelsynchronization may be performed for transmitting date on the uplinkfrom UE 204 to eNB 202.

FIG. 6 is a flow diagram 600 illustrating time of arrival (TOA) basedcorrection for uplink channel synchronization for transmission of datafrom an UE, according to an example implementation.

At block 610, a UE (e.g., UE 204) may determine a first time of arrival(TOA) index value. In some implementations, for example, UE 204 maydetermine the first TOA index value based on the first TOA data set tp1(as described above in reference to FIG. 5) received from eNB 202 andsignal physical reception time at the UE. The first TOA data set tp1received from eNB 202 may include signal physical transmission time(T0), update time period t_(P), etc.

In some implementations, for example, UE 204 may determine the first TOAindex value based on [Eq. 11] when the distance between UE 204 and eNB202 changes rapidly and based on [Eq. 12] when the distance between UE204 and eNB 202 does not change rapidly, as shown below:

$\begin{matrix}{T_{toa} = {{int}\left\lbrack \frac{{s{T_{X - 1}\left( {X - 1} \right)}*tpX} + \frac{a{T_{TOA}(X)}*{tpX}^{2}}{2}}{1T_{A}} \right\rbrack}} & \left\lbrack {{Eq}.\ 11} \right\rbrack\end{matrix}$ $\begin{matrix}{T_{toaval} = {{int}\left\lbrack \frac{c*\left( {T_{1X} - T_{0X}} \right)}{1T_{A}} \right\rbrack}} & \left\lbrack {{Eq}.12} \right\rbrack\end{matrix}$

In some implementations, for example, “rapid” movement may be defined asa relative distance change of more than 1 TA (78 m) per second (e.g.,more more than 1 MAC TA update per second may be needed in such a case).

At block 620, UE 204 may receive a first timing advance (TA) correctionindex value from a network node (e.g., gNB 202). In someimplementations, for example, UE 202 may receive a first TA correctionindex value.

At block 630, UE 204 may determine a first time of arrival (TOA)correction value corresponding to the first TA correction value. In someimplementations, for example, UE 204 may determine the first TOAcorrection index value based on [Eq. 7] or [Eq. 8] as described above.

At block 640, UE 204 may determine a first adjusted uplink timing valuebased at least on the first TOA correction value and the first TAcorrection index value. In some implementations, for example, UE 204 maydetermine the first adjusted uplink timing value based on [Eq. 9] asdescribed above.

At block 650, UE 204 may transmit first uplink data based at least onthe first adjusted uplink timing value.

Thus, uplink channel synchronization for transmission of data from theUE to the eNB may be achieved.

Example 1. A method of communications, comprising: determining, by auser equipment (UE), a first time of arrival (TOA) index value;receiving, by the user equipment (UE), a first timing advance (TA)correction index value from a network node; determining, by the userequipment (UE), a first time of arrival (TOA) correction valuecorresponding to the first timing advance (TA) correction index value;determining, by the user equipment (UE), a first adjusted uplink timingvalue based at least on the first time of arrival (TOA) correction valueand the first timing advance (TA) correction index value; andtransmitting, by the user equipment (UE), first uplink data based atleast on the first adjusted uplink timing value.

Example 2. The method of Example 1, further comprising: determining, bythe user equipment (UE), a second time of arrival (TOA) index value;receiving, by the user equipment (UE), a second timing advance (TA)correction index value from the network node; determining, by the userequipment (UE), a second time of arrival (TOA) correction valuecorresponding to the second timing advance (TA) correction index value;determining, by the user equipment (UE), a second adjusted uplink timingvalue based at least on the second time of arrival (TOA) correctionvalue and the second timing advance (TA) correction index value; andtransmitting, by the user equipment (UE), second uplink data based atleast on the second adjusted uplink timing value.

Example 3. The method of any combination of Examples 1-2, furthercomprising: determining, by the user equipment (UE), a second time ofarrival (TOA) index value; receiving, by the user equipment (UE), afirst timing advance (TA) correction index value from the network node;determining, by the user equipment (UE), a second time of arrival (TOA)correction value corresponding to the first timing advance (TA) value;determining, by the user equipment (UE), a second adjusted uplink timingvalue based at least on the second time of arrival (TOA) correctionvalue and the first timing advance (TA) index value; and transmitting,by the user equipment (UE), second uplink data based at least on thesecond adjusted uplink timing value.

Example 4. The method of any combination of Examples 1-3, furthercomprising: transmitting, by the user equipment (UE), the first time ofarrival (TOA) correction value and/or the second time of arrival (TOA)correction value to the network node.

Example 5. The method of any combination of Examples 1-4, furthercomprising: determining whether a distance between the user equipment(UE) and the network node changes rapidly; determining, in response todetermining that the distance between the user equipment (UE) and thenetwork node changes rapidly, the first time of arrival (TOA) indexvalue based on [Eq. 11].

Example 6. The method of any combination of Examples 1-5, furthercomprising: determining whether a distance between the user equipment(UE) and the network node changes rapidly; determining, in response todetermining that the distance between the user equipment (UE) and thenetwork node does not change rapidly, the first time of arrival (TOA)index value based on [Eq. 12].

Example 7. The method of any combination of Examples 1-6, wherein firsttiming advance (TA) correction value is received from the network nodevia a random access response (RAR) message of a random access procedureinitiated by the user equipment (UE).

Example 8. The method of any combination of Examples 1-7, wherein therandom access response (RAR) is a second message (Msg 2) of the randomaccess procedure, and wherein the random access procedure is a four-steprandom access procedure.

Example 9. The method of any combination of Examples 1-8, wherein therandom access response (RAR) is a second message (Msg B) of the randomaccess procedure, and wherein the random access procedure is a two-steprandom access procedure.

Example 10. The method of any combination of Examples 1-9, wherein thefirst timing advance (TA) correction index value is received via atiming advance (TA) command from the network node.

Example 11. The method of any combination of Examples 1-10, wherein thesecond timing advance (TA) correction index value is received via amedia access control (MAC) control element (CE) update from the networknode.

Example 12. The method of any combination of Examples 1-11, wherein thesecond timing advance (TA) correction index value is received when theuser equipment (UE) is in a radio resource control (RRC)_CONNECTEDstate.

Example 13. The method of one of any combination of Examples 1-12,wherein the first and/or second time of arrival (TOA) values aredetermined based on corresponding signal physical transmission times(T0) and signal physical reception times (T1).

Example 14. An apparatus comprising at least one processor and at leastone memory including computer instructions, when executed by the atleast one processor, cause the apparatus to perform a method of anycombination of Examples 1-13.

Example 15. An apparatus comprising means for performing a method of anycombination of Examples 1-13.

Example 16. A non-transitory computer-readable storage medium havingstored thereon computer executable program code which, when executed ona computer system, causes the computer system to perform the steps ofany combination of Examples 1-13.

Example 17. A method of communications, comprising: determining, by auser equipment (UE), a first time of arrival (TOA) based timing advanceindex value; receiving, by the user equipment (UE), a first timingadvance (TA) correction index value from a network node; validating, bythe user equipment (UE), the first timing advance (TA) correction indexvalue received from the network node, the validating based at least onthe first time of arrival (TOA) based timing advance index value; andtransmitting, by the user equipment (UE), a first uplink data based atleast on the first timing index (TA) value that has been successfullyvalidated.

Example 18. The method of Example 17, further comprising: determining,by the user equipment (UE), a second time of arrival (TOA) based timingadvance index value; receiving, by the user equipment (UE), a secondtiming advance (TA) correction index value from the network node;validating, by the user equipment (UE), the second timing advance (TA)correction index value received from the network node, the validatingbased at least on the second time of arrival (TOA) based timing advanceindex value; and transmitting, by the user equipment (UE), second uplinkdata based at least on the one or more second timing advance (TA) valuesthat have been successfully validated.

Example 19. An apparatus comprising at least one processor and at leastone memory including computer instructions, when executed by the atleast one processor, cause the apparatus to perform a method of anycombination of Examples 17-18.

Example 20. An apparatus comprising means for performing a method of anycombination of Examples 17-18.

Example 21. A non-transitory computer-readable storage medium havingstored thereon computer executable program code which, when executed ona computer system, causes the computer system to perform the steps ofany combination of Examples 17-18.

FIG. 7 is a block diagram of a wireless station (e.g., user equipment(UE)/user device or AP/gNB/MgNB/SgNB) 700 according to an exampleimplementation. The wireless station 700 may include, for example, oneor more RF (radio frequency) or wireless transceivers 702A, 702B, whereeach wireless transceiver includes a transmitter to transmit signals anda receiver to receive signals. The wireless station also includes aprocessor or control unit/entity (controller) 704/708 to executeinstructions or software and control transmission and receptions ofsignals, and a memory 706 to store data and/or instructions.

Processor 704 may also make decisions or determinations, generateframes, packets or messages for transmission, decode received frames ormessages for further processing, and other tasks or functions describedherein. Processor 704, which may be a baseband processor, for example,may generate messages, packets, frames or other signals for transmissionvia wireless transceiver 702 (702A or 702B). Processor 704 may controltransmission of signals or messages over a wireless network, and maycontrol the reception of signals or messages, etc., via a wirelessnetwork (e.g., after being down-converted by wireless transceiver 702,for example). Processor 704 may be programmable and capable of executingsoftware or other instructions stored in memory or on other computermedia to perform the various tasks and functions described above, suchas one or more of the tasks or methods described above. Processor 704may be (or may include), for example, hardware, programmable logic, aprogrammable processor that executes software or firmware, and/or anycombination of these. Using other terminology, processor 704 andtransceiver 702 together may be considered as a wirelesstransmitter/receiver system, for example.

In addition, referring to FIG. 7, a controller (or processor) 708 mayexecute software and instructions, and may provide overall control forthe station 700, and may provide control for other systems not shown inFIG. 7, such as controlling input/output devices (e.g., display,keypad), and/or may execute software for one or more applications thatmay be provided on wireless station 700, such as, for example, an emailprogram, audio/video applications, a word processor, a Voice over IPapplication, or other application or software. Moreover, a storagemedium may be provided that includes stored instructions, which whenexecuted by a controller or processor may result in the processor 704,or other controller or processor, performing one or more of thefunctions or tasks described above.

According to another example implementation, RF or wirelesstransceiver(s) 702A/702B may receive signals or data and/or transmit orsend signals or data. Processor 704 (and possibly transceivers702A/702B) may control the RF or wireless transceiver 702A or 702B toreceive, send, broadcast or transmit signals or data.

The aspects are not, however, restricted to the system that is given asan example, but a person skilled in the art may apply the solution toother communication systems. Another example of a suitablecommunications system is the 5G concept. It is assumed that networkarchitecture in 5G will be quite similar to that of the LTE-advanced. 5Gis likely to use multiple input—multiple output (MIMO) antennas, manymore base stations or nodes than the LTE (a so-called small cellconcept), including macro sites operating in co-operation with smallerstations and perhaps also employing a variety of radio technologies forbetter coverage and enhanced data rates.

It should be appreciated that future networks will most probably utilizenetwork functions virtualization (NFV) which is a network architectureconcept that proposes virtualizing network node functions into “buildingblocks” or entities that may be operationally connected or linkedtogether to provide services. A virtualized network function (VNF) maycomprise one or more virtual machines running computer program codesusing standard or general type servers instead of customized hardware.Cloud computing or data storage may also be utilized. In radiocommunications this may mean node operations may be carried out, atleast partly, in a server, host or node operationally coupled to aremote radio head. It is also possible that node operations will bedistributed among a plurality of servers, nodes or hosts. It should alsobe understood that the distribution of labor between core networkoperations and base station operations may differ from that of the LTEor even be non-existent.

Implementations of the various techniques described herein may beimplemented in digital electronic circuitry, or in computer hardware,firmware, software, or in combinations of them. Implementations may beimplemented as a computer program product, i.e., a computer programtangibly embodied in an information carrier, e.g., in a machine-readablestorage device or in a propagated signal, for execution by, or tocontrol the operation of, a data processing apparatus, e.g., aprogrammable processor, a computer, or multiple computers.Implementations may also be provided on a computer readable medium orcomputer readable storage medium, which may be a non-transitory medium.Implementations of the various techniques may also includeimplementations provided via transitory signals or media, and/orprograms and/or software implementations that are downloadable via theInternet or other network(s), either wired networks and/or wirelessnetworks. In addition, implementations may be provided via machine typecommunications (MTC), and also via an Internet of Things (IOT).

The computer program may be in source code form, object code form, or insome intermediate form, and it may be stored in some sort of carrier,distribution medium, or computer readable medium, which may be anyentity or device capable of carrying the program. Such carriers includea record medium, computer memory, read-only memory, photoelectricaland/or electrical carrier signal, telecommunications signal, andsoftware distribution package, for example. Depending on the processingpower needed, the computer program may be executed in a singleelectronic digital computer or it may be distributed amongst a number ofcomputers.

Furthermore, implementations of the various techniques described hereinmay use a cyber-physical system (CPS) (a system of collaboratingcomputational elements controlling physical entities). CPS may enablethe implementation and exploitation of massive amounts of interconnectedICT devices (sensors, actuators, processors microcontrollers, . . . )embedded in physical objects at different locations. Mobile cyberphysical systems, in which the physical system in question has inherentmobility, are a subcategory of cyber-physical systems. Examples ofmobile physical systems include mobile robotics and electronicstransported by humans or animals. The rise in popularity of smartphoneshas increased interest in the area of mobile cyber-physical systems.Therefore, various implementations of techniques described herein may beprovided via one or more of these technologies.

A computer program, such as the computer program(s) described above, canbe written in any form of programming language, including compiled orinterpreted languages, and can be deployed in any form, including as astand-alone program or as a module, component, subroutine, or other unitor part of it suitable for use in a computing environment. A computerprogram can be deployed to be executed on one computer or on multiplecomputers at one site or distributed across multiple sites andinterconnected by a communication network.

Method steps may be performed by one or more programmable processorsexecuting a computer program or computer program portions to performfunctions by operating on input data and generating output. Method stepsalso may be performed by, and an apparatus may be implemented as,special purpose logic circuitry, e.g., an FPGA (field programmable gatearray) or an ASIC (application specific integrated circuit).

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andany one or more processors of any kind of digital computer, chip orchipset. Generally, a processor will receive instructions and data froma read only memory or a random access memory or both. Elements of acomputer may include at least one processor for executing instructionsand one or more memory devices for storing instructions and data.Generally, a computer also may include, or be operatively coupled toreceive data from or transfer data to, or both, one or more mass storagedevices for storing data, e.g., magnetic, magneto optical disks, oroptical disks. Information carriers suitable for embodying computerprogram instructions and data include all forms of non volatile memory,including by way of example semiconductor memory devices, e.g., EPROM,EEPROM, and flash memory devices; magnetic disks, e.g., internal harddisks or removable disks; magneto optical disks; and CD ROM and DVD-ROMdisks. The processor and the memory may be supplemented by, orincorporated in, special purpose logic circuitry.

1-21. (canceled)
 22. An apparatus comprising: at least one processor;and at least one memory including computer program code; the at leastone memory and the computer program code configured to, with the atleast one processor, cause the apparatus at least to: determine a firsttime of arrival index value; receive a first timing advance correctionindex value from a network node; determine a first time of arrivalcorrection value corresponding to the first timing advance correctionindex value; determine a first adjusted uplink timing value based atleast on the first time of arrival correction value and the first timingadvance correction index value; and transmit, a first uplink data basedat least on the first adjusted uplink timing value.
 23. The apparatus ofclaim 22, wherein the at least one memory and the computer program codeconfigured to, with the at least one processor, cause the apparatus atleast to: determine a second time of arrival index value; receive afirst timing advance correction index value from the network node;determine a second time of arrival correction value corresponding to thefirst timing advance correction index value; determine a second adjusteduplink timing value based at least on the second time of arrivalcorrection value and the first timing advance correction index value;and transmit a second uplink data based at least on the second adjusteduplink timing value.
 24. The apparatus of claim 22, wherein the at leastone memory and the computer program code configured to, with the atleast one processor, cause the apparatus at least to: transmit at leastone of the first time of arrival correction value or the second time ofarrival correction value to the network node.
 25. The apparatus of claim22, wherein the at least one memory and the computer program codeconfigured to, with the at least one processor, cause the apparatus atleast to: determine whether a distance between the apparatus and thenetwork node changes faster than a predetermined threshold; anddetermine, in response to determining that the distance between theapparatus and the network node changes faster than the predeterminedthreshold, the first time of arrival index value based on$T_{toa} = {{{int}\left\lbrack \frac{{s{T_{X - 1}\left( {X - 1} \right)}*tpX} + \frac{a{T_{TOA}(X)}*{tpX}^{2}}{2}}{1T_{A}} \right\rbrack}.}$26. The apparatus of claim 22, wherein the at least one memory and thecomputer program code configured to, with the at least one processor,cause the apparatus at least to: determine whether a distance betweenthe apparatus and the network node changes faster than a predeterminedthreshold; and determine, in response to determining that the distancebetween the apparatus and the network node does not change faster thanthe predetermined threshold, the first time of arrival index value basedon$T_{toaval} = {{{int}\left\lbrack \frac{c*\left( {T_{1X} - T_{0X}} \right)}{1T_{A}} \right\rbrack}.}$27. The apparatus of claim 22, wherein the first timing advancecorrection index value is received from the network node via a randomaccess response message of a random access procedure initiated by theapparatus.
 28. The apparatus of claim 27, wherein the random accessresponse is a second message of the random access procedure, and whereinthe random access procedure is a four-step random access procedure. 29.The apparatus of claim 27, wherein the random access response is asecond message of the random access procedure, and wherein the randomaccess procedure is a two-step random access procedure.
 30. Theapparatus of claim 22, wherein the first timing advance correction indexvalue is received via a timing advance command from the network node.31. The apparatus of claim 22, wherein the first time of arrival indexvalue is determined based on corresponding signal physical transmissiontime and signal physical reception time.
 32. The apparatus of claim 22,wherein the apparatus comprises at least part of a user equipment. 33.The apparatus of claim 22, wherein the at least one memory and thecomputer program code configured to, with the at least one processor,cause the apparatus at least to: determine a second time of arrivalindex value; receive a second timing advance correction index value fromthe network node; determine a second time of arrival correction valuecorresponding to the second timing advance correction index value;determine a second adjusted uplink timing value based at least on thesecond time of arrival correction value and the second timing advancecorrection index value; and transmit a second uplink data based at leaston the second adjusted uplink timing value.
 34. The apparatus of claim33, wherein the second timing advance correction index value is receivedvia a media access control control element update from the network node.35. The apparatus of claim 34, wherein the second timing advancecorrection index value is received when the apparatus is in anRRC_CONNECTED state.
 36. The apparatus of claim 33, wherein the secondtime of arrival index value is determined based on corresponding signalphysical transmission time and signal physical reception time.
 37. Anapparatus comprising: at least one processor; and at least one memoryincluding computer program code; the at least one memory and thecomputer program code configured to, with the at least one processor,cause the apparatus at least to: determine a first time of arrival basedtiming advance index value; receive a first timing advance correctionindex value from a network node; validate the first timing advancecorrection index value received from the network node, the validatingbased at least on the first time of arrival based timing advance indexvalue; and transmit a first uplink data based at least on the firsttiming index correction index value that has been successfullyvalidated.
 38. The apparatus of claim 37, wherein the at least onememory and the computer program code configured to, with the at leastone processor, cause the apparatus at least to: determine a second timeof arrival based timing advance index value; receive a second timingadvance correction index value from the network node; validate thesecond timing advance correction index value received from the networknode, the validating based at least on the second time of arrival basedtiming advance index value; and transmit a second uplink data based atleast on the one or more second timing advance correction index valuesthat have been successfully validated.
 39. The apparatus of claim 37,wherein the apparatus comprises at least part of a user equipment.
 40. Amethod of communications, comprising: determining, by a user equipment,a first time of arrival index value; receiving, by the user equipment, afirst timing advance correction index value from a network node;determining, by the user equipment, a first time of arrival correctionvalue corresponding to the first timing advance correction index value;determining, by the user equipment, a first adjusted uplink timing valuebased at least on the first time of arrival correction value and thefirst timing advance correction index value; and transmitting, by theuser equipment, a first uplink data based at least on the first adjusteduplink timing value.
 41. The method of claim 40, wherein first timingadvance correction index value is received from the network node via arandom access response message of a random access procedure initiated bythe user equipment.